Milling machine for cam shafts and the like



Jan. 22, 1935. w. SINCLAIR 1,988,520

MILLING MACHINE FOR CAM SHAFTS AND THE LIKE Filed March 31, 1930 llSheets-Sheet 1,

. lNVENTOR 74 222 2&7 8 x7262 a 2) BY v ATTORNEYS Jan. 22, 1935. w s cMILLING MACHINE FOR CAM SHAFTS AND THE LIKE Filed March 31, 1930 llSheets-Sheet 2 lNVENTOR 74 223748??? 6 277 62a 2) Jan. 22, 1935. w s c A1,988,520

MILLING MACHINE FOR CAM SHAFTS AND THE LIKE Filed March 31, 1950, 11Sheets-Sheet 3 ZZZ INVENTOR W222 6:72 6/2 in ATTORN YS' Jan. 22, 1935. wsmcL l 1,988,520

MILLING MACHINE FOR CAM SHAFTS AND THE LIKE I Filed March 31, 1930 11Sheets-Sheet 4 xms Jan. 22, 1935. w. SINCLAIR MILLING MACHINE FOR CAMSHAFTS 'AND THE LIKE Filed March 51, 1930 11 Sheets-Sheet 5 BY J LuO/vt/7767 A TORNEYS Jan. 22, 1935.

W. SINCLAIR MILLING MACHINE FOR CAM SHAFTS AND THE LIKE Filed March 31,1950 11 Sheets-Sheet '6 INVENTOR k5" 9- ATTO mS' Jan. 22, 1935. w.SINCLAIR MILLING MACHINE FOR CAM SHAFTS AND THE LIKE l1 Sheets-Sheet 7Filed March 51, 1930 INVENTOR 7/02/2472; SzzcZazr BY J FGTZRW 11Sheets-Sheet 8 Jan. 22, 1935.' w. SINCLAIR MILLING MACHINE FOR CAMSHAFTS AND THE LIKE Filed March 31, 1950 v /VVV/////// T N E CV h m z ,WJ v M a N$ lwv W $0O iilfl' I Jan. 22, 1935.

Filed March 31, 1930 W. SINCLAIR MILLING MACHINE FOR CAM SHAFTS AND THELIKE l1 Sheets-Sheet 9 III lNVENTOR 7VZZZZMW/ 5 27w 24 z)" BY M 5 WWATT6% Jan. 22, 1935. w. SINCLAIR 1,988,520

- MILLINGMACHINE FOR CAM 'SHAFTS AND THE LIKE Filed March 51, 1950 11Sheets-Sheet 10 WE'ZZZa/W 8272c lair ATTO NE Jan. 22, 1935. w. SINCLAIRMILLING MACHINE FOR CAM SHAFTS AND THE LIKE Filed March 31, 1930 llSheets-Sheet ll INVENTOR iWzZZzkwr 5172 cZa zr Patented Jan. 22, I935 g:21.

- UNITED sTATes OFFICE MILLING MACHINE Fore oAMsHA-F'rs 'THEE'RLIZKE.William SinclairpDetroit, Mich,1assignor toPro duction EngineeringCompany,jDetroit, Mich.', aeorpQrat-ionof-Michigan f Application Marc 31,f19s0, Serial No. 44:0;320 9: claims. .('Cl.f oo lan This inventionrelates to milling machines, and mounting in Figure 3, the cover of thegear :box more particularly to machines for milling the being removed;

profiles -of cams or other irregular shapes. Figure- 11 is a verticalsectional view taken;

One of the objects of the-present invention is substantially ontheline'1ll1 of Figure 1 r, the provision of a machine that willsimultane- Figure l2 is a central vertical section through ously mill:all of the cam profiles ona multiple a'modifiedformof my machine whereinthe workcam shaft or like article, whereby a comparaissimultaneouslydriven'fromboth ends. tively quick profiling operation is'secured on the Figure 13 is an endview thereof from the tailentire camshaft instead of necessitating a series stockend, and In ofoperations'on the several camsa Figure '14-isadetailvertioalview'through the Another object of this invention isthe-arrangemeans ior' clamping and adjusting the position ment of amachine having a pair of heads mountof the tailstock. ed for controlledsliding movement longitudinally Referring now to the drawings,the-numeraI- 'IS- of themachine, and eachhead carryingapl-uraldesignates a base of suitable size and contour, if) ity ofspaced milling cutters mounted for conwhich, as herein shown, isarranged to support 15, trolled individual movements laterally oi themathe head stock 1 6, the tail stock 17, and a pair chine during thesliding movements of the heads. of spaced slidable heads 18,- each ofwhich carry A further object of this invention is the proa plurality ofmilling cutters, as hereinafter vision of simple drive mechanismfor-driving the pointed out. The-head stock 16- is utilized inthe 20mechanism for rotating the cam shaft being embodiment shown in Figures1-.11, inclusive, as 20 milled, the several milling cutters and" thecontrol the driving element for the work being milled, mechanismswhereby the heads are slidably for e'xampla'thecam shaft 20 shown inFigure 1 moved and the individual millers advanced orre- The cam shaftis provided with a flange 21 adtracted. jacent oneextremity, and, fordriving purposes Other'objects and advantageswill beapparent herein,this flange is apertured at a distance from 25 g from the followingdescription wherein referthe center of the shaft, a pin 22 suitablylocated once is made to the accompanyingdrawings onthe headstock beingadapted to fit into such showing preferred embodiments-of my invention,aperture and rotatethe cam shaft when the; and wherein similar referencenumerals: desighead stock rotatable elements are being driven. 3o natesimilar parts throughouttheseverall views. The cam shaft 20 is usuallypreliminarily'ma- In the drawings: I chined' to some extent'beforebeingprofiled in my Figure '1 is a plan viewof'my improved machine improvedmachine, as for example, the ends of with a cam shaft in position formilling. the shafts being machined and scored at "the Figure 2 is a sideelevation thereof, with-some centers for locatio-nonmy improved millingniaof the interior'mechanismshown in dotted'lines. chine, and in'addition the center bearingof the 35 Figure 3 is an end'elevation, fromthe tail'stoek camshaft is machined to also aid in location end. 1herein. 'In addition the material between the Figure 4 is a centrallongitudinal section several cams20 might be ground out or other--through the machine with the camshaftremoved-p wise machined to clearthe side faces of the therefrom. V V a several cams.

Figure 5 is an enlarged vertical cross section The mechanismfor drivingthe head stock 16 taken substantially on theline 55 of Figure 1', willnow be described, and at the same time the looking in the direction ofthe arrows. v p coaction between such mechanismand the re- Figure 6 is asimilar cross section taken submai-ning driving mechanisms will be'pointedou-t.

stantially on the, line 66-of Figure. 1, A single mote-r24 is mountedonabracke'tat one 45 a Figure 7 is an enlarged longitudinal detail see,-side ofthe machinebed and its shaft is contional view'takensubstantially on the line 7-7 nested-through the flexible coupling 25-'(note Fig-- of Figurerl. ure6) Withllh pinion 26, suitably journaled inFigure 8 is a vertical section taken substantially bearings on theremovable cover plate '27. The on the line 8--'8 of Figure 7., a pinion-26 meshes with a pinion 28 at one extrem- 50 Figure 9 is a longitudinalvertical section taken ity of" the elongated" shaft 29 which extendscomsubstantially on the line 9-4! of Figure l. pletelyacross theframework of 'themachine and Figure 10 is a vertical detail view showingthe carries adjacent its opposite extremity a pair of mounting of theshafts and pick-01f gears in the, pfinions-BO and 31' respectively.(Note Figures 6 gear 'box diametrically opposed to the motor and-lli)The pinion 31 meshes with api-nionfi-Z 37 the shaft carries a wormpinion 38 which meshes with a worm-gear 39 keyed-on the rotatable arbor40 of the head stock (note Fig1iie'4) to thereby turn this portion ofthe head stock to drive the cam shaft or other work then being milled.The worm pinion '38 alsogmeshe's )with a larger worm gear 41 (noteFigures 4 and 6), which is keyed on the shaft 42, suitably journaled inspaced bearings in the framework lS longitudi-i nally of the machine andbelow the work'bein'g milled. The shaft 42 is adapted to receive a'plurality of master cams 43, eachfashioned to properly control themovements of a milling cutter, as hereinafter described, the mastercams" being keyed upon the shaft 42, as by the elongated key 44, andpositioned longitudinallyof the shaft any suitable.- manner: On theshaft 42 isalso keyed a spur gear 45;(noteFigures 4 and 8) which mesheswitha pair of gears 46and 46 respectivelybolted or otherwise secured atone extremity of the: cam-slotteddrums 47 and 47 (note Figure 7). Theslotted drums 47 and 47 are mounted to revolve on stub shafts 48securedin the framework of themachine at either sideof the head stock, and theperipheral cam slots in such drums receive pins 49 and 49%,extendingthroughelongatedslots 50 in the framework of the machine and secured attheir upper extremitiesin the slidable cutter heads 18, which, as bestshown in Figures 7 and 8, are slidably mounted in dovetail slots 51exten ing longitudinally of the machine. The; slots in the cam drums 47,47, may be suitably shaped and positioned ,to

, -;reciprocate theslidable heads 18 in, any desired manner, as forexample to slide thecutter'head slowly inonedirection; for a majorportion of the cam slot and then rapidly return the head to its originalposition. Inactual use it is preferred g-that one head18 be slid in onedirection during the profiling operation on the cam shaft while theother-head is being slid in theopposite direc tion, and both are rapidlyreturned to their initial positions.

by means of aplurality of wormpinions 52 splined on an elongatedshaft 53and meshing with worm gears 54 mounted on the cutter-carrying shafts(note Figures 9 and 2); The shaft, 53 is journaledlin speced'bearings'int s b t '1 made for initially adjusting the position of the head 18 andat its forward extremity is provided with a.multiple splined portion 55slidably fitted within the hub 56 of the worm gear57, which meshes withthe worm pinion 58,- keyed or otherwise suitably secured on theelongatedshaft 59, which extends laterally across the framework of v themachine-andis 'journaled at its ends in suitable bearings 60 (noteFigure 6). The cutters-in the'other slidable head 18 are similarlyconstructsingle. motor 24 ,driving mechanisms are suitably I chine head15.

Adjacent priate speeds. Such driving mechanisms are compactly arrangedin the embodimentillustrated. in Figures 1-11 at one extremity of thema- Moreover, the pinions 26, 28, 30, *31,.3,2;and 34 are mountedadjacent the extremities of their respective shafts so that they can bereadily removed from the shafts and replaced by pi'nions' with;different numbers of teeth or the like, in the" "manner of pick-offgears. Such pinions are normally enclosed by cover plates, as thecover-plates27, 2? in Figures 6 and 11. Accordingly, any desired changesin speed ofcertain of the'shafts relatively to other shafts may readilybe obtained. Q r

The tailxstock 17 is mounted inlongitudinal alignment with the headstock 16 and includes a longitudinally movable member-17 which may bemoved toward or from'the head stock upon rotationof the hand wheel 17through suitable mechanism, in the usual manner of tail stocks.

The milling cutter. mechanisms are best shown in Figures 5 and 37'. 'Ihecutters 62 are removably mounted at the inner ends of the shafts 63 inany suitable manner, and the; shafts 63 are mounted for rotation inspaced bearings 64 in slidable quills 65, which as best shown in-Figure5, are mounted for sliding movement in bushings 66 in the heads 18. Thequi1ls65 are normally pressed outwardly away from thework being milledby means of a plurality of coil springs 67 arranged between a portion ofthe head 18 and a collar 68 carried by the quill. The shaftm63 isprovided, with a multiple-spline 63*? which'interfits with the hub ofits worm pinion 54'whereby the sliding of the quill may be effectedduring the continued rotation ofthe shaft 63 and its attached millingcutter 62. The sliding movement of the quill is herein shown ascontrolled from the mastercams 43, an arm 69 being pivoted'between itsends on the shaft 70 and connected adjacent one extremity with thecollar 68 of the quill, as by the pivot pin '71.

7 The other extremity of the arm 69 carries a roller Ineach slidablecutterhead 18 are arranged a." plurality of milling cutter jmechanisrns,as; best shown in Figures 1, 4 and 9, simultaneously driven '72 whichbears against the periphery of the master cam 43 cooperating therewith.-The springs 67 serveto maintain the roller 72in constant contact withthe surface of the master cam 43 through pressing outwardly on thecollar 68 to'which' one extremity of the arm 69, is pivotally secured.

;As best shown in Figure 7, provision may be milling cutter 62relatively to the work being milled. As herein shown, the quill isformed with a rack portion '73 which meshes with the pinion 74 suitablymounted in theupper portion of the collar68; so that rotation of thepinion 74 will slide the quill 6 5- relatively to the collar 68 wheneverthe; collar is loosened from the quill. To permit ready'loosening andclamping of the collars 68.upon the quills 65, whenever desired, I haveshown in Figure 7 each collar 68 provided with oneofits sides. split, asby the horizontal slot 68 and then provide an elongated shoulder bolt'75 threading into the portion of the collar below the slot, wherebyrotation of the bolt in onedirection will serve to tend to,close'the'slot 68 and thereby' firmly clamp the collar 68 upon the quillV 65, while rotation of the bolt inthe opposite dirjeee tioni will serveto :loo'senfthecollar :andffreer. "the; Eigure;.1-,;,and .xthe otherhead .18 islidtowardthe quillfor longitudinal adjustment:as.:desired.

' The. operation of, my; improved; machine. is; believedto beapparent... .Assume-that;ibis/desired to profile the cams on the cam;shaft ofa four:

cylinder mot-or, which shaft 20. hasrbeenzprelimi-x. narily machinedbetweenthecams and toipr'ovide end and center bearings": The .endstof:the shafti are also preliminarily-,1 scored at their; centers,

while the flange of the camshafitiszprovidedi with anaperture radiallyoffset-from thecenter' ofthe shaft. "Theme-am is then 'p'ositionedzintothe machine; by;.withdrawing:.theatailistocky 1:'7,-;:then placingtherscoredjcenter-pfi one end ofithe ishaftf against the pointedcenteriof theheadstock; liGtfi-ik-S s: element 1:6 and:v thenguidingntheacamx shaft. fihge,.;so that its aperture .iitsssnugly overthe projecting pin 22 on the headstock 16i.-.-"I'l -1e;cen-. tralhearing: of" the cam sh'aftis then loweredsinto engagement with the:.lowier. half? or "the: bridge bearing. 76,. whereupon? the frailstockrlfi is ad vanced by turning themand wheel 117 1.130 bringthepointedxcenter ofthe tailtstock into the sco'red center at theadjacent'gendof the camshaft. The hinged cover flfierisitheni swung overthe center bearing'of the'cam shaft. c-iThiS operation of inserting thecam shaft-to be. milledisiqui-te simplein practice and therotatinghead-stockand other mechanisms of 1 the machine-need not' bestopped toeither withdraw .the finished cam shaft or .insert .alnew one.on the headstock intoithe aperture of the camfiange is. readily doneby..afifeeling ioperation after; the scoredv center of the camshaft endis placed upon the pointed center: ofithe' head stock. The outward and.inward movement' of thei tail stock is also quickly secured'by 'spinningthe hand wheel 17*, while the:- semicircular cup on "the bridge; bearing"16 for'the center bearing of the cam shaftprovides a ready means forguiding-thecam shaftcafter the pin- 22" has been inserted in theaperture. in the cam shaft flange and the camshaft accordingly rotated;Moreover; this bear ing 76 soholds the rotating camshaft that the--pointed center'of the tail stock accuratelyseats in the scored center ofthe adjacent 'end -of 'the cam shaft. The milling cutter's' 62' arenormally moved laterally awayfrom the work, and accordingly. do. notinterfere with the: removal fof a finished camshaft or the insertion ofa neW- one,--'

but in an effort to safeguard the-workmen, I pref erably provide guards7 7 in: spaced relation around the upper portions of the milling cutterswhile they are in their outermost positions- (note Figure 5). I I

After the master cams 43 have been secured'inproper relation upon theshaft 42, the profiling operation of the several cams oneach cam shaft20.is= substantially automatic'.- The 'shaft-42 car rying the master.cams 43 1s geared for 'sirnulta-- necus rotation from the same shaftthat drives Simultaneously the several milling cutters are be ingrotated at desired speeds through the shafts 53,,and the heads18.carrying the'milling cutters are reciprocated longitudinally. iOfthemachine through the grooved cams: 4'7 and associated mechanism.Preferably one. of the-heads. I8. is. slid. toward the head stock-from.the initial posi-. tion shown inFigure-L to thereb'yzmill the-profiles.7Q; ofv the cams. at. the right? of: the :m-illingcutters in:

The locating'of the pin 22 followedi'byi'a comparatively. rapid return,though.. otheriarrangementsmay be made to suit the con-,

ditions of'the-work.:being..milled.. If desired, the

rotating parts; may beautomatically stoppedafter thecompletionof'theprofilingoperation on each cam! shaft .or'other work 'anduthe workremovedandxireplaced: whilei 'the rotating mechanism isstopped. However,byproperly timing the remoyingsandreplacing operation withthe return of":the milling cutters tosoriginal :position. by the grooves .inithe camdrum'47, I am enabled to keep therotating. elements in constantmotionfor long periods of time. Figures .12 and. 14, inclusive,

Ihave shown an embodiment of my invention that is' particularlyusefulwith cam shafts that are of: comparatively greaterlength and relative--.s1enderness,."such for example as the cam shaft-for eight cylinderengines. In this embodiment, I drive both ends. of the. work beingmilled; and as .herein shown, the con nection for driving the tail:stock is from the shaft42' carrying; the master cams 43' and pinion 45in my first .describedembodiment. The shafit 42. is made of requisitethickness. and strength to accommodate driving the tail stock of myimproved: machine, and. adjacent its opposite ends it carries. the wormgear 41 and the spur gear'78 =(note Figure 12). Thegear. '78 iscomparativelywide and. meshes with the narrower" pinion 79 .securedlon.the rotating portion of the tailstock :80,"which. is mounted in suitablebearings-81in the framework of the machine. The forward extremityof thetail stock is herein shown as provided with a recess ear the receptionof a spring-pressed plunger 82, which is maintained bythe ,coil spring.83 normally beyond the remainder-ofthe tail stock except when inengagement with, the. work to be milled. This plunger 82 is within thehollow 'center of a spring collet 95 (note Figure 12) having inclinedouter surfaces on its spaced jaws which cooperate with the taperedforward extremity of the barrel portion 80.of=the' tail stock, so as tofirmly grip the adjacentcam extremity or other work to be milled inthe-usual manner of spring collets whenever the collet isthrust'forwardly into engagement with the tapered forward extremity ofthe barrel. To

move, the spring collet longitudinallywithin the barrelasdesired, I haveprovided the rear-extremity of ,the .collet with a central threadedaperturewithwhich cooperates the threaded forwardportiono-f the shaft85, which ,carriesat its v rear extremity a hand wheel 84, and isprovided intermediateits endsv with a collar 96 which abuts against awasher 97 secured at the extremity of the barrel ,80 so as to preventtraveling of the shaft 85 when the hand wheel is rotated. Accordinglywhenever the hand. wheel 841s turned in one direction, its threadedportion will'cooperate with the threaded portion of the collet so as tomovethe collet towardtherear extremity of the barrel 80, and so withdrawthe spring jaws of the collet from engagement with the a work beingmilled, while rotation of the hand wheel in the opposite directionwilliserve to advance the collet within the-barrel 80 toagain clamp. thejaws-about the flange on the work in contact the head stock. I

As best illustrated in clamping it in any adjusted position.- In.this'construction the tail stock is provided with a flared sideportion. 80 fitting in a fixed dovetail groove 86 at its lower extremityand cooperating witha flared pivoted clamping member -8'7-.at-.its.upper extremity. The central portionof the side portion 80 ofthe tail' stock carries a rack-88 which meshes with a pinion ;89 carriedat the lower extremity of the. vertical shaftr91, .whichis-ajour-g naledin a hollow externally threaded sleeve 90 which sleeve threads within aninternally threaded bushing 98 fixed within an apertureiin the framework and providedwith a bottom flange 99 arranged to prevent upwardtravel of. the. bushing.

when the sleeve 90 is rotated. The upperlex-i tremity of the sleeve 90is'provided with a polygonal portion about which fits the hub ofv ahandle 92, and just below such. polygonal portion the sleeve is providedwith an outwardly flanged portion having a rounded lower edge which fitswithin a recess in the pivoted clamping member 87. The verticalshaft 91carries a handle 93 at its upper extremity in any suitable manner..

By virtue of this construction, when the handle 92 on the sleeve ispartially rotated" the'sleeve rides upwardly within the bushing 98,releasing the pressure formerly exerted upon-the clamping member 87through .the flange 94Iof the sleeve. With the pivoted clamping member87 thus loosened from the tail stock rotationof the shaft handle 93 willrotate the pinion, 89, and through the rack 88 will cause thelongitudinal movement.

of the tail stock. When the desired new. position of the tail stock hasbeen reached the sleeve handle 92 is turned in the reverse direction,whereby the sleeve 90 is drawn downwardly .within the bushing 98 andexerts pressure through the flange 94 upon the pivoted clampingmember,87 to again clamp the tail stock in the adjusted position.

It will accordingly be evidentthat with vari-;

Suitable lubrication for the several rotating parts and coolant for thecutters are supplied in the usual manner or in any desired manner. Itwill be noted that thebearing 76 for'the' center bearing on the camshaft 20, is bridged over from the sides of the machine framework so asto permit the liquid lubricant or coolant to fiowwithout interruption. v

While it will be apparent that the illustrated embodiments of myinvention herein disclosed are well calculated to adequately fulfill theob jects and advantages primarily stated, it is to be understood thatthe invention is susceptible to variation, modification and changewithin the spirit and scope of the subjoined claims. I claim:

1. In a milling machine, the combination aligned head stock andtailstock for receiving.

Figures 12 to 14 .I'have'. also provided novel means for readilymoving'the: tail stock longitudinally of the. machine andv work to bemilledyapair of longitudinally slidable heads arranged :in spacedrelation with re spect tosaid stocks;-:a plurality of 'milling cuttersarranged and 'laterallymovable in each of said heads, cam and levermeans for independently moving each of said milling cutters laterally toand from the work-longitudinally sliding the heads and rotatably drivingsaid cutters, all actuable from asingle source of power.

2. In amilling machine, the combination of a rotary work'holder, aipairof longitudinally slidable .heads .mounted at the sides of the workholder, a plurality of milling cutters mounted and laterallyimovable inea'ch head, means-for sliding said-heads, means for rotating the millingcutters, and cam and levermeans for laterally moving the milling cuttersduring the longitudinal sliding movementsof said heads.

3. In a milling machine, the combination-of a rotary work holder, a pairof slidable heads mounted at the sides of the work holder, a pluralityof millingcutters mounted in each head and independently transverselymovable with respect thereto, means'for sliding said heads in oppositedirections, a rotatable master shaft, a plurality of master cams.removably mounted thereon, means for rotating the milling cutters whilesaid heads are being slid, and means controlled by said master camsv forindependently moving the milling cutters transversely of said heads,including a plurality .of levers fulcrumed intermediate their ends; andeachhavingone of its extremities secured. to one of the milling cutters,and its other extremity in constant contact with a master cam.

4.. Ina milling. machine, the combination of a rotarywwork holder, apair of slidable heads mounted at the sides of the work holder, aplurality of milling? cutters mounted'in each head movable transverselythereof, and each comprising a rotatable shaft, a slidable quill inwhich the shaft is rotatably mounted,,and a collar adjustably mounted onthe quill, a rotatable master cam shaft, a plurality of master camsremovably mounted thereon, and means controlled by said master cams andconnected with said collars for independently sliding the millingcutterstransversely of the heads. r

.5. Inamilling machine, the combination of a rotary ;work holder, 'apair. of slidable heads mounted at the sides of the work holder, aplurality of milling cutters mounted in each head movable transverselythereof, and each comprising a rotatable shaft-,a slidable quill inwhich the shaft is rotatably mounted, and a collar adjustably mounted onthe quill, a rotatable master cam shaft, a plurality of master camsremovably mounted thereon, and means controlled by said master cams andconnected with said collars for independently sliding the millingcutters transversely-:of'the heads, comprising-a plurality of levershaving their extremities respectively engaging said master cams andcollars.

6. In a milling machine, the combination of a rotary work holder, a pairof slidable heads mounted, at the sides of the work holder, a pluralityof milling cutters mounted in each head movable ,transverselythereof,and each comprising ,a rotable shaft, a slidable quill in which theshaft is rotatably mounted,.and a 'collar adjustably mounted'o'n thequill, a rotatable master cam shaft; a plurality of master camsremovably mounted .-;thereon,' means controlled by said master cams andconnected with said collars for independently sliding the millingcutters transversely; of the heads, and means for driving the severalrotatable elements from a single source of power.

7. In a milling machine, the combination of a rotatable work holder, apair of slidable heads at the sides of the work holder, a plurality ofmilling cutters rotatably and transversely slidably mounted in eachhead, a master cam shaft rotatably mounted below the work holder, amotor, means for driving the work holder, master cam shaft and themilling cutters from the motor, means comprising a drum cam actuated bythe master cam shaft for sliding the said heads longitudinally of thework,v and lever means also actuated thereby for sliding the millingcutters transversely of said heads.

8. In a milling machine, the combination of a rotatable work holder, apair of slidable heads at the sides of the work holder, a plurality ofmilling cutters rotatably and transversely slidably mounted in eachhead, a master cam shaft rotatably mounted below the work holder, amotor, means for driving the work holder, master cam shaft and themilling cutters from the motor, means including a pair of cam drumsrotated from the motor for sliding saidheads, and means actuated fromthe master cam shaft for independently sliding the milling cutterstransversely of said heads.

9. In a milling machine, the combination of a rotatable work holder, apair of slidable heads at the sides of the work holder, a plurality ofmilling heads, including a plurality of levers pivoted intermediatetheir ends and each having its upper extremity connected with anon-rotatable portion of a milling cutter, and its lower extremity 20 incontact with a rotatable portion on the master cam shaft.

WILLIAM SINCLAIR.

